<template>
  <div class="spec-preview">
    <img :src="imgObj.imgUrl" />
    <div class="event" @mousemove="handler"></div>
    <div class="big">
      <img :src="imgObj.imgUrl"  ref="big"/>
    </div>
    <div class="mask" ref="mask"></div>
  </div>
</template>

<script>
import EventBus from "@/utils/eventBus"; // 导入 EventBus
console.log(EventBus);

export default {
  name: "ZoomPage",
  props: ["skuImageList"],
  data(){
    return{
      currentIndex:0
    }
  },
  computed: {
    imgObj() {
      return this.skuImageList[this.currentIndex] || {};
    },
  },
  mounted() {
    EventBus.$on("getIndex", (index) => {
      this.currentIndex=index
    });
  },
  methods:{
    handler(event){
      let mask=this.$refs.mask;
      let big=this.$refs.big;
      let left=event.offsetX-mask.offsetWidth/2;
      let top=event.offsetY-mask.offsetTop/2;
      if(left<=0){left=0}
      if(left>=mask.offsetWidth){left=mask.offsetWidth}
      if(top<=0){top=0}
      if(top>=mask.offsetHeight){top=mask.offsetHeight}
      mask.style.left=left+'px';
      mask.style.top=top+'px';
      big.style.left=-2*left+'px';
      big.style.top=-2*top+'px'
    }
  },
};
</script>

<style lang="less">
.spec-preview {
  position: relative;
  width: 400px;
  height: 400px;
  border: 1px solid #ccc;

  img {
    width: 100%;
    height: 100%;
  }

  .event {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 998;
  }

  .mask {
    width: 50%;
    height: 50%;
    background-color: rgba(0, 255, 0, 0.3);
    position: absolute;
    left: 0;
    top: 0;
    display: none;
  }

  .big {
    width: 100%;
    height: 100%;
    position: absolute;
    top: -1px;
    left: 100%;
    border: 1px solid #aaa;
    overflow: hidden;
    z-index: 998;
    display: none;
    background: white;

    img {
      width: 200%;
      max-width: 200%;
      height: 200%;
      position: absolute;
      left: 0;
      top: 0;
    }
  }

  .event:hover ~ .mask,
  .event:hover ~ .big {
    display: block;
  }
}
</style>